We need to measure the radius of gyration of met-myoglobin that has been reacted with an excess of [Co(acacen)(NH3) 2]Cl (acacen meaning acetylacetonate diimine). Our work shows that the resulting protein product is partially unfolded and is bound to 6 cobalt complexes. Possible applications for such species range from molten globules as toxin like pro-drugs to improved protein production in industrial scales. They may be instrumental in the study of protein aggregation in connection with amyloidases or the prion disease, and in the study of protein folding. A radius of gyration --provided by SAXS-- will provide us with the first indication of the underlying structure of this protein-metal complex.